Online payment to casual workers - whether it is mandatory for a contractor to pay wages to its employees in their bank accounts directly?

I am civil contractor in a central PSU. Having less than 20 casual labourers on roll. I comply with PF & ESI formalities for all my employees. I want to know that whether it is mandatory for a contractor to pay wages to its employees in their bank accounts directly.

Rather than see whether it is mandatory or not,see the convenience of all-workers and organisation.Bank payment to designated a/c of workers is the best proof of payments done and long term record.Take written declaration from employees of bank details with blank cheque and send only to bank on time.